Method of manufacturing integrated circuit device with bonding structure

ABSTRACT

A circuit device includes: a first substrate having a first barrier layer; a second substrate having a second barrier layer; a first conductive portion arranged over the first barrier layer; a second conductive portion arranged over the second barrier layer; a first expanding pad arranged on the first conductive portion and including a first contact area greater than that of the first conductive portion; and a second expanding pad bonded to the first expanding pad, arranged on the second conductive portion and including a second expanded contact area greater than that of the second conductive portion. The first barrier layer and the second barrier layer include aluminum fluoride.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of U.S. Non-Provisional application Ser. No. 17/582,220 filed Jan. 24, 2022, which is a divisional application of U.S. Non-Provisional application Ser. No. 16/440,292 filed Jun. 13, 2019, now U.S. Pat. No. 11,315,871 B2, which disclosures are incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a method of manufacturing an integrated circuit device, and more particularly, to a method of forming an integrated circuit device with a bonding structure.

DISCUSSION OF THE BACKGROUND

Integrated circuits are broadly used in electronic devices. In the integrated circuit industry, continual reductions in a minimum feature size allow more components to be integrated into a given area. A recent development is three-dimensional integrated circuits (3DICs), in which multiple semiconductor dies are stacked upon one another, using packaging techniques such as package-on-package (PoP) and system-in-package (SiP). Some 3DICs are prepared by placing dies over dies on a semiconductor wafer level. 3DICs provide an improved integration density and other advantages, such as a faster speed and a greater bandwidth.

While seeking ways to decrease length of interconnects between the stacked dies, alignment of two substrates becomes crucial because a poor alignment can cause misplacement of interconnects of the two substrates. For example, if a conductive portion of a substrate fails to be suitably coupled to another conductive portion of another substrate due to poor alignment, a conductivity defect will likely occur. However, it would be inefficient to pursue perfect alignment during the semiconductor manufacturing process, since that would require a significant increase in the process time.

This Discussion of the Background section is provided for background information only. The statements in this Discussion of the Background are not an admission that the subject matter disclosed in this section constitutes prior art to the present disclosure, and no part of this Discussion of the Background section may be used as an admission that any part of this application, including this Discussion of the Background section, constitutes prior art to the present disclosure.

SUMMARY

One aspect of the present invention provides a circuit device. The circuit device includes: a first substrate having a first barrier layer; a second substrate having a second barrier layer; a first conductive portion arranged over the first barrier layer; a second conductive portion arranged over the second barrier layer; a first expanding pad arranged on the first conductive portion and including a first contact area greater than that of the first conductive portion; and a second expanding pad bonded to the first expanding pad, arranged on the second conductive portion and including a second expanded contact area greater than that of the second conductive portion. The first barrier layer and the second barrier layer include aluminum fluoride.

Another aspect of the present invention provides a method of manufacturing an integrated circuit device. The method includes: providing a first substrate having a first barrier layer; providing a second substrate having a second barrier layer; forming a first conductive portion over the first barrier layer; forming a second conductive portion over the second barrier layer; forming a first expanding pad over the first conductive portion to provide a first expanded contact area greater than that of the first conductive portion; and forming a second expanding pad over the second conductive portion to provide a second expanded contact area greater than that of the second conductive portion. The first barrier layer and the second barrier layer include aluminum fluoride.

Yet another aspect of the present invention provides a method of manufacturing an integrated circuit device. The method includes steps of: providing a first semiconductor device having a first recess; providing a second semiconductor device having a second recess; forming a first barrier layer and a second barrier layer in the first and second recesses, respectively the first barrier layer and the second barrier layer including aluminum fluoride; depositing a first conductive portion and a second conductive portion on the first barrier layer and the second barrier layer, respectively; and forming a first expanding pad or a second expanding pad on the first conductive portion or the second conductive portion, respectively, the first expanding pad or the second expanding pad has a greater contact area as compared to the first conductive portion or the second conductive portion.

With the above-mentioned configurations of the integrated circuit device and methods of manufacturing the same, the conductive portions of two substrates both have respective expanding pads so that the contact area can be increased. Further, the material of the barrier layer is selected such that the likelihood of corrosion in the underlying conductive features can be reduced. Hence, the conductivity problem caused by poor alignment can be alleviated, and the reliability of the integrated circuit device can be enhanced.

The foregoing has outlined rather broadly the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter, and form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It should be noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a flowchart showing a method for manufacturing an integrated circuit, in accordance with some embodiments.

FIGS. 2A to 2F are cross-sectional illustrations of different stages of a method for manufacturing an integrated circuit device, in accordance with some embodiments.

FIG. 3 is a flowchart showing a method for manufacturing an integrated circuit, in accordance with some embodiments.

FIGS. 4A to 4E are cross-sectional illustrations of different stages of a method for manufacturing an integrated circuit device, in accordance with some embodiments.

FIG. 5 is a flowchart showing a method for manufacturing an integrated circuit, in accordance with some embodiments.

FIGS. 6A to 6D are cross-sectional illustrations of different stages of a method for manufacturing an integrated circuit device, in accordance with some embodiments.

FIGS. 7A to 7B are cross-sectional illustrations of different stages of a method for manufacturing an integrated circuit device, in accordance with some embodiments.

FIGS. 8A to 8B are cross-sectional illustrations of different stages of a method for manufacturing an integrated circuit device, in accordance with some embodiments.

FIG. 9 is a flowchart showing a method for manufacturing an integrated circuit, in accordance with some embodiments.

FIG. 10 is a cross-sectional illustration of a stages of a method for manufacturing an integrated circuit device, in accordance with some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

FIG. 1 is a flowchart showing a method 100 for manufacturing an integrated circuit in accordance with some embodiments of the present disclosure. In some embodiments, the method 100 includes a number of steps (102, 104, 106, 108 and 110), and the description and illustrations below are not deemed as a limitation to the sequence of the steps 102 through 110.

FIGS. 2A to 2F are cross-sectional illustrations of different stages of manufacturing an integrated circuit device 20 in accordance with some embodiments of the present disclosure. Referring to FIG. 2A, a cross-sectional illustration of a portion of a first semiconductor device 200 and a portion of a second semiconductor device 300 are shown in accordance with some embodiments. In step 102, a first semiconductor substrate 202 having a first conductive portion 214 above the first semiconductor substrate 202 is provided. In some embodiments, if the first conductive portion 214 is made of a metal, such as copper, which is easy to diffuse, then a diffusion barrier layer 216 is needed to prevent the metal from diffusing. The diffusion barrier layer 216 may be made of silicon nitride (SiN), silicon oxynitride (SiON), titanium nitride (TiN), tantalum nitride (TaN), or aluminum nitride (AlN). In some embodiments, the first conductive portion 214 is made of copper, and the diffusion barrier layer 216 is made of Ti, TiN, Ta, TaN, Ta/TaN, CoP or CoW. In some embodiments, the diffusion barrier layer 216 has a thickness in a range from about 5 Å to about 1000 Å.

As illustrated in FIG. 2A, the first semiconductor device 200 includes a first device region 210, and a metallization structure is formed to individually connect to the first device regions 210. The details of the first device region 210 and the metallization structure are illustrated below. In some embodiments, the metallization structure includes an interconnect structure, such as contact plugs 218 and first conductive features 212. The conductive features 212 are embedded in an insulating material 206. In some embodiments, the insulating material 206 is made of silicon oxide. In some embodiments, the insulating material 206 includes multiple dielectric layers of dielectric materials. The first conductive features 212 are connected to the first conductive portions 214 so that the first device regions 210 are also electrically connected to the first conductive portions 214. The first conductive portion 214 may be made of conductive materials, such as copper (Cu), copper alloy, aluminum (Al), aluminum alloy, or combinations thereof. Other applicable materials may be used to form the first conductive portion 214. The metallization structure shown is merely for illustrative purposes. The metallization structure may include other configurations and may include one or more conductive lines and via layers.

In some embodiments, the first semiconductor substrate 202 may be made of silicon or other semiconductor materials according to the knowledge in the field. For example, in some embodiments, the first semiconductor substrate 202 may include other elementary semiconductor materials such as germanium. In some embodiments, the first semiconductor substrate 202 is made of a compound semiconductor such as silicon carbide, gallium arsenic, indium arsenide, or indium phosphide. In some embodiments, the first semiconductor substrate 202 is made of an alloy semiconductor such as silicon germanium, silicon germanium carbide, gallium arsenic phosphide, or gallium indium phosphide. In some embodiments, the first semiconductor substrate 202 includes an epitaxial layer. For example, the first semiconductor substrate 202 has an epitaxial layer overlying a bulk semiconductor layer.

In step 104, a second semiconductor substrate 302 having a second conductive portion 314 above the second semiconductor substrate 302 is provided. In some embodiments, as shown in FIG. 2A, the second semiconductor device 300 is similar to the first semiconductor device 200. The second semiconductor device 300 includes the second semiconductor substrate 302, second device regions 310, and a metallization structure, which is formed to individually connect to the second device regions 310. The details of the second device region 310 and the metallization structure are illustrated below.

In some embodiments, the metallization structure includes an interconnect structure, such as contact plugs 318 and conductive features 312. The conductive features 312 are embedded in an insulating material 306. In some embodiments, the insulating material 306 is made of silicon oxide. In some embodiments, the insulating material 306 includes multiple dielectric layers of dielectric materials. The metallization structure shown is merely for illustrative purposes. The metallization structure may include other configurations and may include one or more conductive lines and via layers. In some embodiments, the metallization structure may further include a diffusion barrier layer 316, which is similar to the diffusion barrier layer 216.

The second semiconductor substrate 302 is similar to the first semiconductor substrate 202, and thus may also be made of silicon or other semiconductor materials according to the common knowledge in the field. In some embodiments, the second semiconductor substrate 302 includes an epitaxial layer. For example, the second semiconductor substrate 302 has an epitaxial layer overlying a bulk semiconductor layer.

Referring to FIG. 2B, a cross-sectional illustration of a portion of the first semiconductor device 200 and a portion of the second semiconductor device 300 are shown in accordance with some embodiments. In step 106, a first chemical reaction 201 is performed to form a first expanding pad 215 on the first conductive portion 214 to provide a first expanded contact area 215A that may be, for example, 10% larger than the first conductive portion 214. In some embodiments, the first conductive portion 214 is copper, and the first chemical reaction 201 includes germanidation of copper. In order to achieve the germanidation of copper, the first semiconductor substrate 202 is brought to a pre-clean temperature which is preferably equal to the soak temperature, followed by a plasma-assisted pre-clean performed in-situ at a declining pressure. The resulting germanide is a copper germanide (Cu₃Ge) alloy, and the first expanding pad 215 is formed accordingly. By applying an in-situ plasma-assisted cleaning process, the native copper oxide (CuO) present on the copper film is removed before the exposure to the germanium precursor, thereby facilitating the solid-vapor reaction between copper and the germane gas. Comparative studies have shown that the in-situ plasma-assisted cleaning process leads to better germanidation of copper having an orthorhombic crystalline as compared with an ex-situ plasma-assisted cleaning process. In some embodiments, a chemical mechanical polishing (CMP) process may be performed prior to the first chemical reaction 201. As illustrated in FIG. 2B, at least a portion of sidewalls of the first conductive portion 214 is exposed through the first polymer material 208 to facilitate the subsequent first chemical reaction 201. In some embodiments, the exposed portion of sidewalls of the first conductive portion 214 is in direct contact with the first expanding pad 215.

According to some embodiments of the present disclosure, the germanium precursor employed in the first chemical reaction 201 may be germane, e.g., GeH₄, supplied in the presence of a carrier gas to induce a catalyzed chemical vapor reaction. Preferably, the carrier gas is N₂. The flow rate of the germane precursor (GeH₄) can be adjusted to the desired partial pressure in the PECVD chamber where the germanidation takes place. This partial pressure of the germanium precursor in the reactor may be, for example, between 70 and 420 mTorr.

Furthermore, it has been found that the soak time, the partial pressure of the Ge precursor (GeH₄) and the soak temperature (also referred to as the germanidation temperature) are interrelated variables that must be selected according to the thickness of the chosen metal films. In some embodiments, the soak temperature for any of the copper (Cu), nickel (Ni) and cobalt (Co) films is maintained in the range between 250° C. and 400° C.

In some embodiments, the germanidation in the first chemical reaction 201 may be replaced with similar processes. For example, the precursor may be methane (CH₄) or silane (SiH₄) to obtain copper-carbon cluster or copper fill, respectively. Since the principle of the chemical reaction using the precursor above is similar, a detailed description of the corresponding process is thus not repeated for the sake of conciseness.

In step 108, a second chemical reaction 301 is performed to form a second expanding pad 315 on the second conductive portion 314 to provide a second expanded contact area 315A that may be, for example, 10% larger than the second conductive portion 314. In some embodiments, the second conductive portion 314 is copper, and the second chemical reaction 301 includes germanidation of copper as described above. In some embodiments, a CMP process is performed prior to the second chemical reaction 301. As illustrated in FIG. 2B, at least a portion of sidewalls of the second conductive portion 314 is exposed through the second polymer material 308 to facilitate the subsequent second chemical reaction 301. In some embodiments, the exposed portion of sidewalls of the second conductive portion 314 is in direct contact with the second expanding pad 315.

Referring to FIG. 2C, a cross-sectional illustration of a portion of the first semiconductor device 200 and a portion of the second semiconductor device 300 are shown in accordance with some embodiments. As can be seen in FIG. 2C, the first semiconductor device 200 and the second semiconductor device 300 are arranged to face each other for the subsequent bonding processes. In step 110, the first semiconductor substrate 202 of the first semiconductor device 200 is bonded to the second semiconductor substrate 302 of the second semiconductor device 300 with a hybrid bonding structure 400 so that the first expanded contact area 215A is substantially in direct contact with the second expanded contact area 315A.

As illustrated in FIG. 2C, a first bonding structure 220 is formed over the metallization structure of the first semiconductor device 200. The first bonding structure 220 includes the first conductive portion 214 embedded in a first polymer material 208 and the first expanding pad 215 embedded in a second polymer material 222. The first conductive portion 214 may be, in some embodiments, a contact pad (or a bond pad) formed on a top surface of the first semiconductor device 200. In some embodiments, the first polymer material 208 is benzocyclobutene (BCB) polymer, polyimide (PI), or polybenzoxazole (PBO). In some embodiments, the second polymer material 222 is made of a BCB polymer and is applied to the metallization structure by spin coating. Since the BCB polymer is a soft material, it can tolerate more stress resulting from TSV formed during the subsequent processes, compared to other dielectric materials such as silicon dioxide.

The second bonding structure 320 is similar to the first bonding structure 220 and includes the second conductive portion 314 embedded in a third polymer material 308 and the second expanding pad 315 embedded in the fourth polymer material 322. The second conductive portion 314 is similar to the first conductive portion 214, and the third and fourth polymer materials 308 and 322 are similar to the first and second polymer materials 208 and 226, respectively.

Before the first semiconductor device 200 is bonded to the second semiconductor device 300, the first and second semiconductor devices 200 and 300 are aligned, such that the first expanding pad 215 on the first conductive portion 214 can be bonded to the second expanding pad 315 on the second conductive portion 314 and the second polymer material 222 on the first semiconductor device 200 can be bonded to the fourth polymer material 322 on the second semiconductor device 300. In some embodiments, the alignment of the first and second semiconductor devices 200 and 300 may be achieved by using an optical sensing method. As illustrated, with the first and second expanding pads 215 and 315, it is not necessary for the alignment to be perfect, but a fine bonding result can still be achieved.

Referring to FIG. 2C, after the alignment is performed, the first and second semiconductor devices 200 and 300 are bonded together by hybrid bonding to form a 3DIC stacking structure 20 (die stack). The first and second semiconductor devices 200 and 300 are hybrid bonded together by application of pressure and heat. In some embodiments, during hybrid bonding, the stacking structure 20 is heated to a temperature in a range from about 100° C. to about 200° C., such that the polymer materials 208, 222, 308 and 322 become a non-confined viscous liquid and are reflowed. By reflowing the polymer materials 208, 222, 308 and 322, voids therein are eliminated.

Next, the stacking structure 20 is further heated to a higher temperature in a range from about 220° C. to about 380° C., such that the expanding pads 215 and 315 are interconnected by thermocompression bonding and the polymer materials 208, 222, 308 and 322 are fully cured. In some embodiments, the pressure for hybrid bonding is in a range from about 0.7 bar to about 10 bar. The hybrid bonding process may be performed in an inert environment, such as an environment filled with inert gas including N₂, Ar, He, or combinations thereof.

As shown in FIG. 2C, hybrid bonding involves at least two types of bonding, including metal-to-metal bonding and non-metal-to-non-metal bonding. As shown in FIG. 2C, the hybrid bonding structure 400 is formed between the first and second semiconductor devices 200 and 300. The hybrid bonding structure 400 includes the expanding pads 215 and 315 bonded by metal-to-metal bonding and the polymer materials 222 and 322 bonded by non-metal-to-non-metal bonding. As shown in FIG. 2C, the bonding structure 400 has a metallic bonding interface between the expanding pads 215 and 315 but may not have a clear non-metallic interface between the polymer materials 222 and 322 due to the reflowing process.

Compared to hybrid bonding involving other dielectric layers, the first and second semiconductor devices 200 and 300 are bonded through the polymer materials 222 and 322. Since the bonding of the polymer materials 222 and 322 involves the reflowing of the polymer materials 222 and 322, voids in the polymer materials 222 and 322 are eliminated and the bonding strength of the first and second semiconductor devices 200 and 300 is improved.

Referring to FIG. 2D, a cross-sectional illustration of a portion of the first semiconductor device 200 and a portion of the second semiconductor device 300 are shown in accordance with some embodiments. As illustrated, each of the first device regions 210 includes a gate structure embedded in a dielectric layer 204, source/drain regions 211, and isolation structures 213, such as shallow trench isolation (STI) structures. The gate structure includes a gate dielectric layer 207, a gate electrode 209, and optional spacers (not shown). The first device regions 210 shown in FIG. 2D are merely examples, and other structures may be formed in the device regions 210. In some embodiments, the first device regions 210 may form various N-type metal-oxide semiconductor (NMOS) and/or P-type metal-oxide semiconductor (PMOS) devices, such as transistors or memories, and the like, which are interconnected to perform one or more functions. Other devices, such as capacitors, resistors, diodes, photo-diodes, fuses, and the like may also be formed on the first semiconductor substrate 202.

As shown in FIG. 2D, through silicon vias (TSVs) 500 are provided on the first semiconductor substrate 202 and the metallization structure is formed over the TSVs 500 to individually connect the TSVs 500 to the device regions 210. As illustrated, the TSVs 500 are formed between two adjacent device regions 210 and extend into the first semiconductor substrate 202. The TSVs 500 are used to provide electrical connections and for heat dissipation for 3DICs. Although FIG. 2D shows three TSVs, the number of TSVs may be adjusted according to actual application.

As shown in FIG. 2D, each of the TSVs 500 includes a liner 502, a diffusion barrier layer 504, and a conductive material 506 in accordance with some embodiments. In some embodiments, the liner 502 is made of an insulating material, such as oxide or nitride. The liner 502 may be formed using a plasma-enhanced chemical vapor deposition (PECVD) process or other applicable process. The liner 502 may be a single layer or multi-layers. In some embodiments, the liner 502 has a thickness in a range from about 100 Å to about 5000 Å.

In some embodiments, the diffusion barrier layer 504 is made of Ta, TaN, Ti, TiN, or CoW. In some embodiments, the diffusion barrier layer 504 is formed by a physical vapor deposition (PVD) process. In some embodiments, the conductive material 506 is made of copper (Cu), copper alloy, aluminum (Al), aluminum alloy, or combinations thereof. Alternatively, other applicable materials may be used. In some embodiments, the conductive material 506 is formed by plating.

With high aspect ratios, filling materials into the TSV opening becomes challenging. Voids may form in a TSV opening. In addition, due to the insufficient sidewall coverage of the liner 502 or the diffusion barrier layer 504, some extrusion or diffusion problems related to the conductive material 506 may occur. In contrast, as shown in FIG. 2D, the TSVs 500 are designed to have a depth D1 less than a height H1 of the first semiconductor device 200. Therefore, the void problems and the extrusion or diffusion problems related to the conductive material 506 are resolved or greatly reduced. In addition, a width W1 of the TSVs 500 is reduced along with a decrease of the depth D1 of the TSVs 500. When a distance W2 is smaller, a larger area of device regions 210 may be used. As a result, integrated density of the devices in device regions 210 is further improved.

In some embodiments, the first semiconductor device 200 has a height H1 from a bottom surface of the first semiconductor substrate 202 to a top surface of the dielectric layer 204 in a range from about 1 pin to about 20 μm. In some embodiments, the TSVs 500 have a width W1 in a range from about 0.025 μm to about 2 μm. In some embodiments, the TSVs 500 have a depth D1 in a range from about 0.2 pin to about 10 μm. In some embodiments, the TSVs 500 have an aspect ratio (D1/W1) in a range from about 2 to about 15. In addition, devices in the vicinity of the TSV suffer from serious performance degradation due to stress induced by the TSV. A keep-out zone (KOZ) is used to define a region in which no devices are allowed to be placed. In some embodiments, the keep-out zone (KOZ) is defined by a distance W2, which is measured from a sidewall of the TSV 500 to a nearest gate structure. Since the depth D1 of the TSVs 500 is reduced, a smaller width W1 is achieved. Therefore, overall stress induced by the TSVs 500 is reduced. In some embodiments, the distance W2 is in a range from 0.01 pin to about 3 pin. In some embodiments, when the width W1 of the TSVs 500 is reduced to a range from about 2 μm to about 3 μm, the stress induced by the TSV can thus almost be ignored.

Similarly, as shown in FIG. 2D, the second semiconductor device 300 is similar to the first semiconductor device 200. The second semiconductor device 300 includes a second semiconductor substrate 302 and second device regions 310. The second semiconductor substrate 302 is similar to the first semiconductor substrate 202. The second device regions 310 are similar to the first device regions 210 and include a gate structure, source/drain regions 311, and isolation structures 313. The gate structure of the second device region 310 is similar to the gate structure of the first device region 210 and includes a gate dielectric layer 307, a gate electrode 309, and optional spacers (not shown). The gate dielectric layer 307 is similar to the gate dielectric layer 207, and the gate electrode 309 is similar to the gate electrode 209. In addition, the source/drain regions 311 in the second device regions 310 are similar to the source/drain regions 211 in the first device regions 210, and the isolation structures 313 in the second device regions 310 are similar to the isolation structures 213 in the first device regions 210.

In some embodiments, as an exemplary process of providing the first semiconductor substrate 202 and the TSVs 500, the first semiconductor substrate 202 and some components arranged around the first substrate 202 are formed. For example, the isolation structures 213, the gate structure and the source/drain regions 211 are successfully formed in the first semiconductor substrate 202. In some embodiments, the dielectric layer 204 is deposited over the first semiconductor substrate 202, followed by the formation of the contact plugs 218 in the dielectric layer 204. The TSVs 500 may be formed on the surface of the dielectric layer 204 and extend through the dielectric layer into a depth of the first semiconductor substrate 202. In some embodiments, the insulating material 206 is deposited over the dielectric layer 204, and the first conductive features 212 are formed in the insulating material 206. In some embodiments, the polymer material 208 is deposited including trenches over the insulating material 206, and the diffusion barrier layer 216 and the first conductive portion 214 are deposited in the trenches the polymer material 208.

In some embodiments, as an exemplary process of providing the second substrate 203, the second substrate 203 and some components arranged around the second substrate 203 are formed. For example, the isolation structures 313, the gate structure and the source/drain regions 311 are successfully formed in the second substrate 203. In some embodiments, the dielectric layer 304 is deposited over the second semiconductor substrate 302, followed by the formation of the contact plugs 318 in the dielectric layer 304. In some embodiments, the insulating material 306 is deposited over the dielectric layer 304, and the first conductive features 312 are formed in the insulating material 306. In some embodiments, the polymer material 308 is deposited including trenches over the insulating material 306, and the diffusion barrier layer 316 and the first conductive portion 314 are deposited in the trenches the polymer material 308.

Referring to FIG. 2E, a cross-sectional illustration of a portion of the first semiconductor device 200 and a portion of the second semiconductor device 300 are shown in accordance with some embodiments. As illustrated, after hybrid bonding, the stacking structure 20 is put on a tape (not shown) and a thinning process 203 is performed on a bottom surface of the first semiconductor device 200. After the thinning process 203, the TSVs 500 are exposed. The thinning process 203 may include a grinding operation and a polishing operation (such as CMP). After the thinning process 203, a wet etching operation is performed to remove the defects formed on the bottom surface of the first semiconductor device 200. In some embodiments, a bottom portion of the diffusion barrier layer 504 is removed to expose the conductive material 506 by the thinning process 203. Therefore, after the thinning process 203, a height H2 is less than the depth D1. In some embodiments, the TSVs 500 have an aspect ratio (H2/W1) in a range from about 2 to about 15. In some other embodiments, the height H2 is equal to the depth D1. After the thinning process 203, the first semiconductor device 200 has a height H2 from the bottom surface of the first semiconductor substrate 202 to a top surface of the dielectric layer 204 in a range from about 0.2 lam to about 10 μm. The height H2 is less than the height H1. In some embodiments, the height H2 is in a range from about 1% to about 99% of the height H1.

It should be noted that if the thinning process 203 is performed before the first and second semiconductor devices 200 and 300 are bonded, the thin first semiconductor device 200 can easily break during subsequent processes. However, if the first and second semiconductor devices 200 and 300 are bonded first, as shown in FIG. 2E, such bonding enables the thinning of the first semiconductor device 200. As a result, the first semiconductor device 200 can be thinned to a relatively smaller height H2 compared to the first semiconductor device 200, which is directly thinned before bonding.

Referring to FIG. 2F, a cross-sectional illustration of a portion of the first semiconductor device 200 and a portion of the second semiconductor device 300 are shown in accordance with some embodiments. As illustrated, an interconnect structure 600 is formed on the bottom surface of the first semiconductor device 200. The interconnect structure 600 is electrically connected to conductive features 212 over the first semiconductor substrate 202 via TSVs 500. The interconnect structure 600 includes conductive features 610, such as conductive lines, vias, or conductive pads, formed in an insulating material 620. The metal routing of the conductive features shown in FIG. 2F is merely an example. Alternatively, other metal routing designs of conductive features may be used according to actual applications.

After the manufacturing of the interconnect structure 600, one or more redistribution layers (RDLs) (not shown) may be formed over the interconnect structure 600. For example, the redistribution layers (RDLs) are embedded in a passivation layer. The interconnect structure 600, the redistribution layers (RDLs) and the TSVs 500 provide electrical interconnection. In addition, since the TSVs 500 have a relatively low resistance, the RC delay is reduced. In addition, other processes may also be performed on the 3DIC stacking structure 20, and the 3DIC stacking structure 20 may be subsequently diced to form individual chips.

FIG. 3 is a flowchart showing a method 700 for manufacturing an integrated circuit, in accordance with some embodiments of the present disclosure. In some embodiments, the method 700 includes a number of steps (702, 704, 706, 708 and 710), and the description and illustrations below are not deemed as a limitation to the sequence of the steps 702 through 710. Steps 702 and 704 are substantially identical to steps 102 and 104 described above. In step 702, a first semiconductor substrate 202 having a first conductive portion 214 above the first semiconductor substrate 202 is provided. In step 704, a second semiconductor substrate 302 having a second conductive portion 314 above the second conductive portion 314 is provided.

FIGS. 4A to 4E are cross-sectional illustrations of different stages of a method for manufacturing an integrated circuit device 40 in accordance with some embodiments. Referring to FIG. 4A, a cross-sectional illustration of a portion of a first semiconductor device 200 and a portion of a second semiconductor device 300 are shown in accordance with some embodiments. In step 706, a first plating process 205 is performed to form a first expanding pad 215 on the first conductive portion 214 to provide a first expanded contact area 215A that may be, for example, 10% larger than the first conductive portion 214. In some embodiments, a CMP process is performed prior to the first plating process 205. As illustrated in FIG. 4A, at least a portion of sidewalls of the first conductive portion 214 is exposed through the first semiconductor substrate 202 to facilitate the subsequent plating process.

In step 708, a second plating process 305 is performed to form a second expanding pad 315 on the second conductive portion 314 to provide a second expanded contact area 315A that may be, for example, 10% larger than the second conductive portion 314. In some embodiments, a CMP process is performed prior to the second chemical reaction 301. As illustrated in FIG. 4A, at least a portion of sidewalls of the second conductive portion 314 is exposed through the second semiconductor substrate 302 to facilitate the subsequent plating process.

Referring to FIG. 4B, a cross-sectional illustration of a portion of a first semiconductor device 200 and a portion of a second semiconductor device 300′ are shown in accordance with some embodiments. In step 710, the first semiconductor substrate 202 of the first semiconductor device 200 is bonded to the second semiconductor substrate 302 of the second semiconductor device 300 with a hybrid bonding structure 400. As illustrated, a 3DIC stacking structure 40 is formed by bonding the first and second semiconductor devices 200 and 300′. As shown in FIG. 4B, the second semiconductor device 300′ is almost the same as the second semiconductor device 300 except that TSVs 800 are formed in the second semiconductor device 300′. In some embodiments, the TSVs 500 have a diameter different from that of the TSVs 800. In some embodiments, the formation of the TSVs 800 involves additional patterning and etching processes. In some embodiments, a quantity of the TSVs 500 is greater than that of the TSVs 800. In some other embodiments, the quantity of the TSVs 500 is less than that of the TSVs 800.

As shown in FIG. 4B, each of the TSVs 800 includes a liner 802, which is similar to the liner 502, a diffusion barrier layer 804, which is similar to the diffusion barrier layer 504, and a conductive material 806, which is similar to the conductive material 506. The diffusion barrier layer 504 is laterally surrounded by the liner 502. The conductive material 806 is laterally surrounded by the diffusion barrier layer 504 and the liner 502. The TSVs 800 extend to a metal pad 312 of the second semiconductor device 300′. Because the second semiconductor device 300′ is later thinned to expose the TSVs 800, the TSVs 800 do not extend through the whole second semiconductor substrate 302 of the second semiconductor device 300′. Therefore, the TSVs 800 are designed to have a depth D2 which is less than an original height H3 of the second semiconductor device 300′.

In some embodiments, the second semiconductor device 300′ has a height H3 from a bottom surface of the second semiconductor substrate 302 to a top surface of the dielectric layer 304 in a range from about 17 pin to about 100 pin. In some embodiments, the TSVs 800 have a width W3 in a range from about 0.3 μm to about 10 μm. In some embodiments, the TSVs 800 have a depth D2 in a range from about 15 pin to about 100 pin. In some embodiments, the TSVs 800 have an aspect ratio (D2/W3) in a range from about 5 to about 15. In some embodiments, the depth D1 is the same as the depth D2. In some other embodiments, the depth D1 is different from the depth D2. In some embodiments, the formation of the second semiconductor substrate 302, the gate structures on the second semiconductor substrate 302 and the TSVs 800 may be similar to the formation of the first semiconductor substrate 202, the gate structures on the first semiconductor substrate 202 and the TSVs 500, and the detailed description thereof is not repeated for brevity.

Referring to FIG. 4C, a cross-sectional illustration of a portion of a first semiconductor device 200 and a portion of a second semiconductor device 300′ are shown in accordance with some embodiments. As illustrated, the first semiconductor device 200 is thinned to a height H2 and an interconnect structure 600′ is formed on a bottom surface of the first semiconductor device 200. The interconnect structure 600′ is similar to the interconnect structure 600 in FIG. 2F, and detailed description of the interconnect structure 600′ is not repeated for brevity.

Referring to FIG. 4D, after the forming of the interconnect structure 600, the stacking structure 40 is put on a tape (not shown) and a thinning process 203 is performed on a bottom surface of the second semiconductor device 300′. After the thinning process 203, the TSVs 800 are exposed. The thinning process 203 is described with reference to FIG. 2E and is not repeated for brevity. After the thinning process 203, the second semiconductor device 300′ has a height H4 from the bottom surface of the second semiconductor substrate 302 to a top surface of the gate structure in a range from about 15 μm to about 100 μm. The height H4 is less than the height H3. In some embodiments, the height H4 is equal to or less than depth D2.

Referring to FIG. 4E, a redistribution (RDL) structure 350 is formed on a bottom surface of the second semiconductor substrate 302. The RDL structure 350 includes a metal pad 352 formed in a passivation layer 354. The metal pad 352 is electrically connected to the exposed TSVs 800. The metal pad 352 is made of conductive materials with low resistivity, such as copper (Cu), aluminum (Al), Cu alloys, Al alloys, or other applicable materials. Although FIG. 4E only shows one RDL structure 350, more than one RDL structure may be formed based on requirements.

As illustrated, an under bump metallization (UBM) layer 358 is formed on the metal pad 352, and a conductive element 356 (such as a solder ball) is formed over the UBM layer 358. The UBM layer 358 may contain an adhesion layer and/or a wetting layer. In some embodiments, the UBM layer 358 is made of titanium (Ti), titanium nitride (TiN), tantalum nitride (TaN), tantalum (Ta), or the like. In some embodiments, the UBM layer 358 further includes a copper seed layer. In some embodiments, the conductive element 356 is made of conductive materials with low resistivity, such as solder or solder alloy. Exemplary elements included in the solder alloy include Sn, Pb, Ag, Cu, Ni, Bi or combinations thereof.

In some embodiments, the interconnect structure 600′ is electrically connected to another package (not shown) on the backside of the second semiconductor device 300′ via the TSVs 800, the RDL structure 350 and the conductive element 356. The TSVs 500 and 800 individually perform different functions. The first semiconductor device 200 is electrically connected to another package structure (not shown) via the interconnect structure 600′ and the TSVs 500. The second semiconductor device 300′ is electrically connected to another package structure (not shown) via the interconnect structure 600′ and the TSVs 800. The TSVs 500 and 800 provide a fast conductive path to connect the first semiconductor device 200, the second semiconductor device 300, and/or other package structures, without the formation of complicated metal routings.

With the above-mentioned configurations of the integrated circuit device 40 and methods 100 and 700 of manufacturing the same, the conductive portions of two substrates both have respective expanding pads so that the contact area can be increased. Hence, the conductivity problems caused by poor alignment can be alleviated.

FIG. 5 is a flowchart showing a method 900 for manufacturing an integrated circuit 60, in accordance with some embodiments. In some embodiments, the method 900 includes a number of steps 1002, 1004, 1006, 1008, 1010, 106, 108 and 110, and the description and illustrations below are not deemed as a limitation to the sequence of the steps 1002 through 1010, 106, 108 and 110.

FIGS. 6A to 6D are cross-sectional illustrations of different stages of the method 900 for manufacturing the integrated circuit device 60 in accordance with some embodiments of the present disclosure. Referring to FIG. 6A, a cross-sectional illustration of a portion of a first semiconductor device 200 and a portion of a second semiconductor device 300 is shown in accordance with some embodiments. In step 1002, a first semiconductor device 200 having first recesses R1 is provided.

As illustrated in FIG. 6A, the first semiconductor device 200 includes a first device region 210, and a metallization structure is formed to individually connect to the first device regions 210. The first semiconductor device 200 further includes a dielectric layer 204, an insulating material 206, a first polymer material 208, first conductive features 212 and first contact plugs 218. The configurations, materials and method of forming the first device region 210, the metallization structure around the first device region 210, the first semiconductor substrate 202, the dielectric layer 204, the insulating material 206, the first polymer material 208, the first conductive features 212 and the first contact plugs 218 illustrated in FIG. 6A are similar to those described with reference to FIG. 2A, and these similar features are not repeated for brevity.

In some embodiments, the first recesses R1 are formed in the first polymer layer 208 and expose portions of the underlying first conductive features 212. The first recesses R1 may be formed by photolithography and etching processes. The etching processes may include a dry etch, a wet etch, a combination thereof, e.g., a reactive ion etch (RIE), or the like.

In step 1004, a second semiconductor device 300 having second recesses R2 is provided. In some embodiments, as shown in FIG. 6A, the second semiconductor device 300 includes a second device region 310, and a metallization structure is formed to individually connect to the second device regions 310. The second semiconductor device 300 further includes a dielectric layer 304, an insulating material 306, a second polymer material 308, second conductive features 312 and second contact plugs 318. The configurations, materials and method of forming the second device region 310, the metallization structure around the second device region 310, the second semiconductor substrate 302, the dielectric layer 304, the insulating material 306, the second polymer material 308, the second conductive features 312 and the second contact plugs 318 illustrated in FIG. 6A are similar to those described with reference to FIG. 2A, and these similar features are not repeated for brevity.

In some embodiments, the second recesses R2 are formed in the second polymer material 308 and expose portions of the underlying second conductive features 312. The second recesses R2 may be formed by photolithography and etching processes. The etching processes may include a dry etch, a wet etch, an RIE, or the like.

In step 1006, a first barrier layer 1106 is formed in the first recesses R1, as shown in FIG. 6B and FIG. 6C. Referring to FIG. 6B, a first barrier material 1102 is deposited in the first recesses R1 and over the first semiconductor substrate 202. The first barrier layer 1106 may be in physical contact with the underlying first conductive features 212. The first barrier material 1102 includes aluminum fluoride. Due to its property of saturated bonds, the aluminum fluoride is stable and can prevent the underlying first conductive features 212 from corrosion caused by various semiconductor processes, especially those processes including fluorine ions. In some embodiments, the first barrier material 1102 further includes zinc oxide, which would increase electrical properties of the first barrier material 1102. In some embodiments, the content of zinc oxide in the first barrier material 1102 is greater than the content of aluminum fluoride. The first barrier material 1102 may be formed by chemical vapor deposition (CVD), atomic layer deposition (ALD), or other applicable deposition processes.

In some embodiments, the first barrier material 1102 is deposited over the surface of the first polymer material 208. The first barrier material 1102 may be conformally disposed in the first recesses R1. Further, the first barrier material 1102 may be disposed on the first conductive features 212 and on the sidewalls of the first recesses R1. The first barrier material 1102 may have a U-shape profile in the first recesses R1 from a cross-sectional view. Each of the first recesses R1 may have a flat bottom surface, and therefore the first barrier material 1202 has a flat bottom surface in the first recesses R1.

Referring to FIG. 6C, an etching operation is performed to remove portions of the first barrier material 1102 over the surface of the first polymer layer 208 and thereby form the first barrier layer 1106 in the respective first recess R1. The etching operation may include a dry etch, a wet etch, an RIE, or the like.

In some embodiment, the first barrier layer 1106 is formed using PVD, e.g., a sputtering process. The source of the sputtering process may include aluminum and sulfur hexafluoride or fluorine. The sulfur hexafluoride or fluorine may be decomposed in plasma and provides fluorination sources, such as fluoride ions and radicals, to react with the deposited films.

In some embodiments, the source of the sputtering process for forming the first barrier material 1202 may include zinc oxide and aluminum fluoride. The sputtering powers for zinc oxide and aluminum fluoride may be about 100 W and 75 W, respectively.

In some embodiments, although not shown in FIG. 6A, the sputtering process may completely fill the first recesses R1 while causing the first polymer material 208 exposed. An etch back process may be performed to reduce the thickness of the first barrier material 1102 in the first recesses R1 to thereby form the U-shaped first barrier layer 1106. The etch rate ratio of the first barrier material 1102 to the first polymer material 208 may be between about 100:1 and about 1.05:1, between about 15:1 and about 2:1, or between about 10:1 and about 2:1 during the etching process.

Likewise, in step 1008, a second barrier layer 1108 is form in the second recesses R2, as shown in FIG. 6B and FIG. 6C. Referring to FIG. 6B, a second barrier material 1104 is deposited in the second recesses R2 and over the second semiconductor substrate 302. The second barrier layer 1108 may be in physical contact with the underlying second conductive features 312. The second barrier material 1104 the same material as the first barrier material 1102, e.g., aluminum fluoride. Due to its property of saturated bonds, the aluminum fluoride is stable and can prevent the underlying second conductive features 312 from corrosion caused by various semiconductor processes, especially those processes including fluorine ions. In some embodiments, the second barrier material 1104 further includes zinc oxide, which would increase electrical properties of the second barrier material 1104. In some embodiments, the content of zinc oxide in the first barrier material 1104 is greater than the content of aluminum fluoride. The second barrier material 1104 may be formed by CVD, ALD, or other applicable deposition processes.

In some embodiments, the second barrier material 1104 is deposited over the surface of the second polymer material 308. The second barrier material 1104 may be conformally disposed in the second recesses R2. Further, the second barrier material 1104 may be disposed on the second conductive features 312 and on the sidewalls of the second recesses R2. The second barrier material 1104 may have a U-shape profile in the second recesses R2 from a cross-sectional view. Each of the first recesses R2 may have a flat bottom surface, and therefore the second barrier material 1204 has a flat bottom surface in the second recesses R2.

Referring to FIG. 6C, an etching operation is performed to remove portions of the second barrier material 1104 over the surface of the second polymer layer 308 and thereby form the second barrier layer 1108 in the respective second recess R2. The etching operation may include a dry etch, a wet etch, an RIE, or the like.

In some embodiment, the second barrier layer 1108 is formed by PVD, e.g., a sputtering process. The source of the sputtering process may include aluminum and sulfur hexafluoride or fluorine. The sulfur hexafluoride or fluorine may be decomposed in plasma and provides fluorination sources, such as fluoride ions and radicals, to react with the deposited films.

In some embodiments, the source of the sputtering process for forming the second barrier material 1204 may include zinc oxide and aluminum fluoride. The sputtering powers for zinc oxide and aluminum fluoride may be about 100 W and 75 W, respectively.

In some embodiments, although not shown in FIG. 6A, the sputtering process may completely fill the second recesses R2. An etch back process may be performed to reduce the thickness of the second barrier material 1104 in the second recesses R2 to thereby form the U-shaped second barrier layer 1108. The etch rate ratio of the second barrier material 1104 to the second polymer material 308 may be between about 100:1 and about 1.05:1, between about 15:1 and about 2:1, or between about 10:1 and about 2:1 during the etch back process.

In step 1010, referring to FIG. 6D, a first conductive portion 214 and a second conductive portion 314 are formed in the respective first recess R1 and second recess R2. The materials, configurations and method of forming for the first conductive portion 214 and the second portion 314 with reference to FIG. 6D are similar to those described with reference to FIG. 2A, and these similar features are not repeated for brevity.

In step 106 of FIG. 5 , referring to FIG. 6D, a first chemical reaction 201 is performed to form a first expanding pad 215 on the first conductive portion 214 to provide a first expanded contact area 215A. Likewise, in step 108 of FIG. 5 , referring to FIG. 6D, a second chemical reaction 301 is performed to form a second expanding pad 315 on the second conductive portion 314 to provide a second expanded contact area 315A. The steps 106 and 108 of the method 900 are similar to the steps 106 and 108 of the method 100. The materials, configurations and method of forming for the first expanding pad 215 and the second expanding pad 315 with reference to FIG. 6D are similar to those described with reference to FIG. 2B, and these similar features are not repeated for brevity.

In step 110 of FIG. 5 , Referring to FIG. 2C, the first semiconductor substrate 202 of the first semiconductor device 200 is bonded to the second semiconductor substrate 302 of the second semiconductor device 300 with a hybrid bonding structure so that the first expanded contact area 215A is substantially in direct contact with the second expanded contact area 315A. The step 110 of the method 900 is similar to the step 110 of the method 100.

FIGS. 7A to 7B are cross-sectional illustrations of different stages of the method 900 for manufacturing an integrated circuit device in accordance with some embodiments. The method 900 described with reference to the cross-sectional illustrations shown in FIGS. 6A to 6D for manufacturing the integrated circuit device 60 can be applicable for manufacturing the integrated circuit device 70 with reference to the cross-sectional illustrations shown in FIGS. 7A and 7B. The integrated circuit device 70 is similar to the integrated circuit device 60 in many aspects, and these similar features are not repeated for brevity. For example, in steps 1002 and 1004, a first semiconductor device 200 having first recesses R1 and a second semiconductor device 300 having second recesses R2 are provided.

The integrated circuit device 70 is different from the integrated circuit device 60 mainly in the formation of a first barrier layer 1202 and a second barrier layer 1204 as described in steps 1006 and 1008, respectively. The first barrier layer 1202 and the second barrier layer 1204 is formed of the same materials as the first barrier layer 1106 and the second barrier layer 1108, which include aluminum fluoride, with a similar deposition method. However, different from the U-shape of the first barrier layer 1106 and the second barrier layer 1108 shown in FIG. 6C, the first barrier layer 1202 and the second barrier layer 1204 include a plate shape or a slab shape, as shown in FIG. 7A. In some embodiments, the first barrier layer 1202 and the second barrier layer 1204 are formed only on the bottom surfaces of the first recesses R1 and the second recesses R2, respectively, instead of being formed the sidewalls of first recesses R1 or the second recesses R2.

The first barrier layer 1202 and the second barrier layer 1204 may be formed by first depositing the first barrier material 1102 and the second barrier material 1204 in a conformal manner in the first recesses R1 and the second recesses R2 using CVD, ALD, or other applicable processes, followed by an etching operation to remove excess materials of the first barrier material 1102 and the second barrier material 1204. Alternatively, the first barrier layer 1202 and the second barrier layer 1204 may be formed by filling the first recesses R1 and the second recesses R2 using a sputtering process, followed by an etching operation to remove excess thicknesses of the first barrier material 1102 and the second barrier material 1204 in the respective first recesses R1 and the second recesses R2.

Referring to FIG. 7B, the remaining steps 1010, 106, 108 and 110 of the method 900 for manufacturing the integrated circuit device may be similar to those for manufacturing the integrated circuit device 60. For example, in step 1010, the first conductive portion 214 and the second conductive portion 314 are formed in the respective first recess R1 and second recess R2. In step 106, a first chemical reaction 201 is performed to form a first expanding pad 215 on the first conductive portion 214 to provide a first expanded contact area 215A. In step 108, a second chemical reaction 301 is performed to form a second expanding pad 315 on the second conductive portion 314 to provide a second expanded contact area 315A. In step 110, the first semiconductor substrate 202 of the first semiconductor device 200 is bonded to the second semiconductor substrate 302 of the second semiconductor device 300 with a hybrid bonding structure, in which the hybrid bonding structure includes the interconnect structure 600 or the RDL structure 350, with reference to FIGS. 2C to 2F or FIGS. 4C to 4E.

FIGS. 8A to 8B are cross-sectional illustrations of different stages of the method 900 for manufacturing an integrated circuit device in accordance with some embodiments. The method 900 described with reference to the cross-sectional illustrations shown in FIGS. 6A to 6D for manufacturing the integrated circuit device 60 can be applicable for manufacturing the integrated circuit device 80 with reference to the cross-sectional illustrations shown in FIGS. 8A and 8B. The integrated circuit device 80 is similar to the integrated circuit device 70 in many aspects, and these similar features are not repeated for brevity.

The integrated circuit device 80 is different from the integrated circuit device 70 mainly in the formation of first recess R3 and second recesses R4 described in steps 1002 and 1004, respectively. The first recesses R3 and the second recesses R4 may be formed using a same or different etching process as compared to that of forming the first recesses R1 and the second recesses R2. Different from the flat bottom surfaces of the first recesses R1 and the second recesses R2 shown in FIG. 6A, the first recesses R3 and the second recesses R4 include a bottom surface with a downward concave shape or a curved shape toward the first conductive feature 212 or the second conductive features 312, as shown in FIG. 8A. In some embodiments, the formation of the first recesses R1 and the second recesses R2 removes portions of the first conductive features 212 and the second conductive features 312 to cause recesses in the first conductive features 212 and the second conductive features 312.

Referring to FIG. 8B, the remaining steps 1006, 1008, 1010, 106, 108 and 110 for manufacturing the integrated circuit device 80 may be similar to those for manufacturing the integrated circuit device and are not repeated for brevity. In some embodiments, a first barrier layer 1206 and a second barrier layer 1208 is formed in each of the first recesses R3 and the second recesses R4, respectively. The first barrier layer 1206 or the second barrier layer 1208 includes a bottom surface having a curved shape conformal to the curvature of the first recess R3 or the second recess R4.

FIG. 9 is a flowchart showing a method 1000 for manufacturing an integrated circuit 90, in accordance with some embodiments. In some embodiments, the method 1000 includes a number of steps 1002, 1004, 1006, 1008, 1010, 106, 108 and 110, and the description and illustrations below are not deemed as a limitation to the sequence of the steps 1002 through 1010, 106, 108 and 110.

FIG. 10 is a cross-sectional illustration of an intermediate stage of the method 1000 for manufacturing the integrated circuit device 90 in accordance with some embodiments of the present disclosure. The method 900 described with reference to the cross-sectional illustrations shown in FIGS. 6A to 6C for manufacturing the integrated circuit device 60 can be applicable for manufacturing the integrated circuit device 90 with reference to the cross-sectional illustration shown in FIG. 10 . The integrated circuit device 90 is similar to the integrated circuit device 60 or 70 in many aspects, and these similar features are not repeated for brevity. For example, in steps 1002 and 1004, a first semiconductor device 200 having first recesses R1 and a second semiconductor device 300 having second recesses R2 are provided. In steps 1006 and 1008, a first barrier layer 1302 and a second barrier layer 1304 are deposited in the first recesses R1 and second recesses R2, respectively. The first barrier layer 1302 and the second barrier layer 1304 is formed of the same materials as the first barrier layer 1106 and the second barrier layer 1108, which include aluminum fluoride, with a similar deposition method. In step 1010, the first conductive portion 214 and the second conductive portion 314 are formed in the respective first recess R1 and second recess R2.

The integrated circuit device 90 is different from the integrated circuit device 60, 70 or 80 mainly in the formation of first expanding pads 215 and second expanding pads 315 shown in FIG. 10 with reference to steps 706 and 708 of FIG. 9 . The steps 706, 708 and 710 of the method 700 shown in FIG. 3 are applicable to the steps 706, 708 and 710 of the method 1000 shown in FIG. 10 . For example, in steps 706 and 708, a first plating process 205 and a second plating process 305 are performed to form the first expanding pads 215 and the second expanding pads 315, respectively, on the first conductive portions 214 and the second conductive portions 314, respectively, to provide an expanded contact area 215A and an expanded contact area 315A, respectively. In step 710, the first semiconductor substrate 202 of the first semiconductor device 200 is bonded to the second semiconductor substrate 302 of the second semiconductor device 300 with a hybrid bonding structure, in which the hybrid bonding structure includes the interconnect structure 600 or the RDL structure 350, with reference to FIGS. 2C to 2F or FIGS. 4C to 4E.

The present disclosure provides advantages. Due to the property of saturated bonds of the aluminum fluoride, potential corrosion in the underlying first conductive features 212 or second conductive features 312 caused by various semiconductor processes, especially those processes including fluorine ions, can be prevented. As a result, the reliability of the integrated circuit device 60, 70, 80 or 90 may be improved.

Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. For example, many of the processes discussed above can be implemented in different methodologies and replaced by other processes, or a combination thereof.

Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, and steps. 

What is claimed is:
 1. A circuit device, comprising: a first substrate having a first barrier layer; a second substrate having a second barrier layer; a first conductive portion arranged over the first barrier layer; a second conductive portion arranged over the second barrier layer; a first expanding pad arranged on the first conductive portion and including a first contact area greater than that of the first conductive portion; and a second expanding pad bonded to the first expanding pad, arranged on the second conductive portion and including a second expanded contact area greater than that of the second conductive portion, wherein the first barrier layer and the second barrier layer comprise aluminum fluoride.
 2. The circuit device of claim 1, wherein the first barrier layer or the second barrier layer includes a plate shape.
 3. The circuit device of claim 1, wherein the first barrier layer or the second barrier layer includes a bottom surface having a curved shape.
 4. The circuit device of claim 1, wherein the first barrier layer or the second barrier layer further comprises zinc oxide, wherein a content of the zinc oxide in the first barrier layer or the second barrier layer is greater than a content of the aluminum fluoride.
 5. The circuit device of claim 1, wherein the first expanding pad or the second expanding pad comprises a material same as a material of the first conductive portion or the second conductive portion.
 6. The circuit device of claim 5, wherein the first expanding pad or the second expanding pad comprises copper germanide.
 7. The circuit device of claim 1, further comprises a first polymer material arranged between the first conductive portion and the second conductive portion and embedding the first expanding pad and the second expanding pad.
 8. The circuit device of claim 1, further comprises a second polymer material embedding the first conductive portion and a third polymer material embedding the second conductive portion.
 9. The circuit device of claim 1, wherein the first substrate further comprises a first gate structure and electrically connected to the first expanding pad, wherein the second substrate further comprises a second gate structure and electrically connected to the second expanding pad.
 10. The circuit device of claim 1, further comprises a first through-substrate via extending through the first substrate and a second through-substrate via extending through the second substrate.
 11. A method of manufacturing an integrated circuit device, comprising: providing a first substrate having a first barrier layer; providing a second substrate having a second barrier layer; forming a first conductive portion over the first barrier layer; forming a second conductive portion over the second barrier layer; forming a first expanding pad over the first conductive portion to provide a first expanded contact area greater than that of the first conductive portion; and forming a second expanding pad over the second conductive portion to provide a second expanded contact area greater than that of the second conductive portion, wherein the first barrier layer and the second barrier layer comprise aluminum fluoride.
 12. The method of claim 11, further comprising bonding the first substrate to the second substrate with a bonding structure.
 13. The method of claim 12, further comprising aligning the first expanding pad with the second expanding pad prior to the bonding.
 14. The method of claim 12, wherein the bonding of the first substrate to the second substrate comprises bonding the first expanding pad to the second expanding pad so that the first expanded contact area is in direct contact with the second expanded contact area.
 15. The method of claim 11, wherein the first conductive portion or the second conductive portion comprises copper.
 16. The method of claim 15, wherein the forming of the first expanding pad or the second expanding pad comprises reacting the copper with germane to obtain copper germanide, reacting the copper with silane to obtain copper fill, or reacting the copper with methane to obtain copper-carbon cluster.
 17. The method of claim 11, further comprising performing a chemical mechanical polishing process to expose at least a portion of a sidewall of the first conductive portion or the second conductive portion through the first substrate or the second substrate, respectively, prior to the forming of the first expanding pad or the second expanding pad.
 18. The method of claim 11, wherein the first barrier layer is in physical contact with the first conductive portion, and the second barrier layer is in physical contact with the second conductive portion.
 19. The method of claim 11, further comprising forming a first gate structure and a second gate structure in the first substrate and the second substrate, respectively.
 20. The method of claim 19, further comprising forming a through-substrate via extending through the first substrate or the second substrate adjacent to the first gate structure or the second gate structure. 